Terrence Williams, who swears one year in China ironed the immaturity out of his game and attitude, is set to finalize a deal with the Celtics that will not only pay him through the rest of this season, but will guarantee him for next season as well, provided he makes the team. The deal will include several triggers that guarantee the contract in stages.

“Time will tell,” Celtics president of basketball operations Danny Ainge said yesterday of whether the talented swingman sticks.

Over a short period Ainge has been able to identify one special trait in Williams’ game. With Rajon Rondo out for the season, Williams is already the best passer on the roster.

“He’s a better passer than anyone on our team,” Ainge said. “He can play (point guard, shooting guard and small forward) and handle the ball. The reason I like Terrence is that we don’t have a true point guard. All of our guys can play the point guard in pinches, and all of them can share ballhandling responsibilities. But Terrence can be the best on our team right now.”

Williams’ problem in the past has been one of immaturity. It has affected his previous NBA stops in New Jersey, Houston and Sacramento.

“I do feel that he’s matured,” Ainge said. “He’s had good coaching over the years, and I’m a little surprised that he struggled to find himself. But this is a big opportunity for him.”

Mark Murphy covered his first NBA season for the Boston Herald in 1989-90, Jimmy Rodgers' last as Celtics coach and a point when injuries were starting to overtake the careers of Larry Bird and Kevin McHale. He was one of the first NBA writers to cover professional basketball in the Olympics with the 1992 Dream Team in Barcelona, and took a detour out to western Massachusetts to chronicle the rise of John Calipari and UMass basketball. He returned to the Celtics beat in 2001, and was on hand for the dawn of a second Big Three era - this time with Paul Pierce, Kevin Garnett, Ray Allen and the Celtics' 17th NBA title in 2008.